Coated waterproof sheeting



State of Illinois,

. simultaneously wit Patented Aug. 14, 1 .923.

UNHTED LESTER KIRSCHBRAUN, 0F EVANSTON, ILLINOIS.

coa'rnn warnnrnoor snnn'rngie.

No Drawing. Application filed February 1, 1919, Serial No. 274,495. Renewed January 27, 1923.

To all whom itmm concern:

Be it known that Lns'ran KmscnnRAUN, a citizen of the United States, residing in the city of Evanston, county of Cook, and have invented. certain new and useful Improvements in Coated Waterproof Sheetings, of which the following is a specification.

This invention relates to improvements in coated waterproof coverings and. process of making same, such, for example, as roofing, and has among its salient objects, to provide a waterproof felted sheet, to which is applied a fibre containing adhesive coating; to provide a product in which the body or felted portion is referably waterproofed the formation of the sheet, although in certain cases the body portion may consist of ordinary saturated felt to which is applied the fibre containing- .coating; to provide a product which permits of the use of relatively low melting point asphalt as a coating; to provide a product in which the coating has a max- 'imum stability and in which the asphalt 'or bitumen is re-inforced against flowing by the fibrous constituents; to provide a product in which very chea fibre of many different kinds can be used and, in general, to provide an improved product and process of the character referred to.

Describing now the preferable way of forming'the product of the present invention, I make an aqueous mixture of water and an emulsifying agent, such, for example, as a clay containing a sufiicient percentage of colloidal particles. To this mixture, and

while it is in a heated condition, is added an adhesive binder while in liquid form,

such as melted asphalt or analo ous bitumens or pitches. The binder is thoroughly amalgamated with the emulsifying agent and water so as to form an emulsi ed matrixin which the binder isin the internal phase and the emulsifying agent and water in the external phase. This matrix is then intimately. mixed with the fibre in a water vehicle. The matrix above referred to may consist, by weight, of fiftyv parts binder, forty parts water and ten parts clay. This mixture, with the fibre added, may be then passed over an ordinary paper or felt machine. As the sheet is formed, the water dries out. and the emulsion is broken, and the bitumen becomes adhesive and intimatenanner heretofore described. is driven out, the heated bitumen becomes ly unites with the fibre. The proportion of ingredients'in-the finished sheet may be as follows: fifty-five per cent of asphalt, eleven per cent of clay and thirty-four per cent of fibre.

After this sheet is formed,.as stated, the coating is applied sheet passes over the the paper machine. The coating mixture, after being formed in the manner hereinafter described, may be applied in the same way as asphalt coating is applied to ordinary saturated felt. The coating in the present invention, as heretofore stated, consists of bitumen and fibre. Preferably, the coating consists of a mixture of an emulsified matrix and fibre formed in the manner heretofore described, except that a much less percentage of fibre is used. For example, the mixture may consist of per last drying rolls of cent of-fibre, the remainder being asphalt and clay. The. emulsion is formed for the reason that the coating can thus be applied cold, but it is not desired to felt the coating; rather, the fibre may be said to more or less float through the asphalt, producing thereby a fibred asphalt coating. F or example, a coating of this character may, in some cases, use asphalt for as low as 140 melting point, whereas, ordinarily, from 200 to 260 -melting point asphalt is used; by melting point of the asphalt is Ineantth'at temperature at which the asphalt begins tomelt when subjected to heat. Various fibres may be used in this coating, such as cheap fibres ordinarily not suitable for making good paper. After the coating is applied, the sheet is run over drying rolls to remove the water. The bitumen then acts in the As the water plastic and a granular facing can then be applied to the adhesive coating. claim as my invention:

. 1. A process of making a waterproof covering consisting in forming a waterproof fibrous sheet, and then applying bitumen coating thereto in an aqueous vehicle containing an emulsifying agent and a minor percentage of fibre.

2. A process of making a waterproof covering consisting in forming a waterproof fibrous sheet, and then applying bitumen coating thereto in an aqueous vehicle containing' an emulsifying agent and a minor preferably after the percentage of fibre, and finally apply a bituminous ingredient thereof to unite with granular facing to the coating while the the fibre,' and then applying a mixture of latter is in heated condition. bituminous emulsified matrix and a fibre 1 3. A process of making a waterproof covto the sheet in an aqueous vehicle and drying 5 ering, consisting in forming a mixture of out the Water.

emulsified bituminous matrix and fibre into a sheet, drying the sheet and permitting the LESTER KIRSGHBRAUN. 

